The text continued: "Want to know why? Phthalates. Phthalates are chemicals often used in pesticides, paints and PVC plastic. But now they're also found in chicken flesh."

The video has been accused of body-shaming men with smaller penises (Photo: Peta)

The video references the National Institutes of Health, saying: "A recent NIH-funded study showed that a mother's poultry consumption during pregnancy correlated with her kid's penis size.

"The more chicken consumed, the smaller the d***."

Getting to the heart of their message, it ends: "Worried about the size of your kid's pecker, mums-to-be? Don't eat chicken."

The video reveals the concerns over chemicals which can be found in meat

Although Peta's scientific findings have not been questioned, there has been criticism that they are body-shaming men with smaller-than-average penises.

Sean O’Callaghan, also known as the blogger Fat Gay Vegan, says: "There is nothing wrong with alerting people to the fact that chemicals in food stuffs can affect the development of their child’s genitalia...

"[But] the campaign is built around the idea that having a bigger penis is better. The second tweet actually reads, 'Your son deserves better'."

Peta have launched the campaign to stop people from eating chicken

He demands that Peta: "Save animals without attacking the self-esteem and emotional well-being of humans."

Mimi Bekhechi, director of Peta, says that the organisation has never subscribed to “bigger is better”.

"But our mission is to get the animal rights message out to as many people as possible – including those who want children with big penises," she told Metro.co.uk.

Peta have defended their campaign saying it's about animals not penises

‘Peta US’ campaign makes the point that our children deserve better than ingesting potentially body-altering chemicals through their food.

"Going meat-free is far from just a vanity issue: eliminating flesh from our plate has been shown to decrease the risk of heart disease, obesity and several types of cancer.

"A vegan diet is optimal for human health while also sparing other animals and their offspring from immense suffering and death."